Dwarf Singapore Pink - Treating Black Spots
I live in Puerto Rico. I have a 4th story Penthouse with a 5th story rooftop terrace. I have many plumeria in very large pots up on my rooftop terrace and allow them to grow to about 8ft before cutting them down in mid winter. I live right next to the ocean, and they are bombarded with a constant breeze (or more) and so they are exposed to every natural airborne substance constantly.
-- Dwarf Singapore Pinks --
These are absolutely the worst. I get black spots on the leaves and these black spots multiply and spread. If I cannot learn to control the black spots, I may get rid of the plants altogether. Here are pictures:
I have come across vague instructions on this forum and I was hoping to get some clarification on the following:
1. What is the name of this, and is it fungal?
2. Exactly what do I use for treating this? Name brands of fungicides that people have used with success would be appreciated.
3. How frequently should I treat the plants (both while black spots are present, and after the battle has been won).
4. Will the damaged leaves repair themselves after the fungus has died, or just eventually fall off. Do I need to cut them off immediately or will treating them stop the spread. At least half of the leaves are infected and cutting them would mean getting rid of most of the leaves.
Thanks in advance for any help on this subject
Here is a link that might be useful: